1. Field of the Invention
The present invention generally relates to decoupling capacitors and more particularly to testing such capacitors having high dielectric material between the metal wirings of the capacitor.
2. Description of the Related Art
Conventional microprocessor clock rates are approaching the gigahertz range of operation and thereby create noise problems. As a result, large decoupling capacitors are used between a power supply and ground to provide enough noise immunity for proper circuit operation. Options include the integration of large plate capacitors, which would essentially occupy the entire chip above the active silicon surface, and trench capacitors embedded in the silicon substrate. However, large plate capacitors add significant critical area and thereby create a difficult yield problem. On the other hand, trench capacitors require extra silicon area which increases the chip size. Both solutions add significant process complexity and cost.